SteamOS announced by Valve, a free operating system "available soon" for living room PCs

The OS “combines the rock-solid architecture of Linux with a gaming experience built for the big screen,” according to the announcement. In-house streaming to a TV, similar to what's used in Nvidia's Shield , is a feature of the OS.

Valve also emphasizes SteamOS's openness. Users can “can alter or replace any part of the software or hardware they want,” and hardware manufacturers are free to “iterate in the living room at a much faster pace,” setting it apart from console-style closed systems.

A vague component of the announcement is Valve's claim to have “achieved significant performance increases in graphics processing” in SteamOS. Valve adds that it's “now targeting audio performance and reductions in input latency at the operating system level.” It's also unclear how many of the 3,000 games on Steam will run natively on SteamOS--Valve says you'll be able to "access the full Steam catalog" through in-home streaming. We're also curious how well the operating system will be suited to desktop PCs or laptops that aren't used in the living room.

Check back on Wednesday for the second of three announcements expected from Valve this week.